V4 DSOCM always reads back zeroes

Hello,

I have a ML403 PPC design (XPS 9.1) that executes code out of DDR. I added 16 KByte of on chip data side BRAM, but the new memory space only seems to read zeroes and ignore writes. I think I checked all the usual suspects: I set the clock ratio to 3 (300 Mhz/ 100 Mhz) through the control register init value, assigned the controller address to a blank space in the PPC's map, I think I've hooked everything up, but still no joy. Same results whether the controller is set for constant BRAM enable on or off, and address range checking on or off.

One other strange thing maybe related - after building, there is a system.bmm and system_stub.bmm file in the ./implementation directory. When I tell XPS to download the file, it errors-out about not finding system_bd.bmm. If I just copy one of the existing bmm files to system_bd.bmm it downloads just fine. And no, none of the apps in my project nor bootloop is marked to be loaded into BRAM. I haven't modified the system.mss file, is this an issue?

Here is an excerpt from the mhs file:

BEGIN ppc405_virtex4 ... BUS_INTERFACE DSOCM = dsocm_v10_0 ... END

BEGIN dsocm_v10 PARAMETER INSTANCE = dsocm_v10_0 PARAMETER HW_VER = 2.00.b PARAMETER C_DSCNTLVALUE = 0x85 PORT DSOCM_Clk = sys_clk_s PORT SYS_Rst = sys_rst_s END

BEGIN dsbram_if_cntlr PARAMETER INSTANCE = dsbram_if_cntlr_0 PARAMETER HW_VER = 3.00.b PARAMETER C_BRAM_EN = 1 PARAMETER C_BASEADDR = 0xE0000000 PARAMETER C_HIGHADDR = 0xE0003FFF PARAMETER C_RANGECHECK = 0 BUS_INTERFACE PORTA = dsbram_if_cntlr_0_PORTA BUS_INTERFACE DSOCM = dsocm_v10_0 END

BEGIN bram_block PARAMETER INSTANCE = bram_block_0 PARAMETER HW_VER = 1.00.a BUS_INTERFACE PORTA = dsbram_if_cntlr_0_PORTA END

Reply to
Jeff Cunningham
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For the record, the problem was apparently the reset signal. Changing from this: PORT SYS_Rst = sys_rst_s to this PORT SYS_Rst = sys_bus_reset solved the problem.

Reply to
Jeff Cunningham

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